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Mayo and Associates, LC <br />~. inflows into the mines were typically not recorded. In other portions of the mines, the <br />coal seam and adjacent rocks aze completely dry. <br />Occasionally, azeas with greater, more persistent inflows are encountered. These sources <br />are usually associated with faults and/or sandstone channels that contain greater <br />quantities of water. Such fault-channel systems are discussed below. <br />Typical hydrographs of roof drips that have not dried up immediately are shown on <br />Figure 9. It is significant to note that the long-term discharges from these sources aze <br />typically less than 2 gpm. Dischazge declines of the hydrographs typically follow an <br />' exponential decay, with the greatest flow rates occurring immediately after the source is <br />' • completely exposed and then falling off rapidly. The tail end of the dischazge <br />hydrograph typically trails off gradually, with slowly decreasing rates of dischazge, Neaz <br />the end of the discharge recession, the dischazge hydrograph may appeaz nearly flat. <br />' Cazbon-14 ages of 6,500 and 12,000 yeazs (Mayo and Associates, 2001) have been <br />determined for groundwater issuing from locations TMA X 32 and 2S X 11, respectively. <br />These ages indicate that the groundwater dischazging from roof drips aze not in active <br />' communication with neaz surface groundwater or surface water. <br />In an attempt to quantitatively evaluate saturated sandstone channels, a dripping channel <br />in the 6th West area of the Deer Creek Mine was investigated (site 6W X 20; Mayo and <br />Associates, 1997c). The channel, located neaz a minor fault with very limited <br />~• displacement, had the dimensions of more than 2,000 feet in length, 150 feet in width, <br />Evaluation of Potential Groundwater Inflows 29 February 24, 2004 <br />Associated with E Seam Mining, <br />West Elk Mine, Somerset, Colorado <br />